Refining of petroleum oil



E. M. CLARK. REFINING OFP-ETROLEUM OIL. APPITICATION FILED APR.21,'191-9 1,4133899. Panted Apr. 25, 1922.

30 fis Tal/k EDGAR M. CLARKOF NEW YORK, N. Y., ASSIGN'OR BAYONNE,NJERSEY, A CORPORATION OF NEW'JERSEY.v

T STANDARD OILCOMPANY, 0F

"' REFINING or rETnoLEUM oir..

. Specification of Letters Patent.

Patented vApr. 25,1922.

Application led April 21, 1919. Serial No. 291,504'.

l To whom t may concern Be it known that I, EDGAR M. CLARK, a. citizenof the United States, residing at New York, in the county of New Yorkand State of New York, have invented a new and useful Improvement inReliningof Petroleum Oil, of which the following is a specification.

My invention relates to improvements'in the art of refining petroleumoil, and will be fully understood from the following specification,taken in connection with the accom panying drawing, which illustratesdiagram matically a refining .apparatus arranged for use according tothe invention.

In the manufacture of light petroleum oils, such as gasoline, there arenow employed on a large scale cracking processes, such,for

example, asthat disclosed in the patent to William M. Burton, No.1,049,667, in which a charge of relatively heavy oil, such as gas oil,is subjected to distillation under highv pressure' (upwards of 4atmospheres), the pressure being maintained not only in the l still butin the condenser as well. In processes such as this, the pressure iscontrolled by regulating the escape of the incondensable gas formedduring the process, this gas being released at the tail-end of thecondenser, usually from a small closed receiving drum into which thecondenser tail-pipe discharges. In accordanceI with my own prior PatentNo.-1,132,163, the receiving drums of a relatively large number ofpressure stills are connected to a single gas pipe and to a singleliquid main. A

In the drawing of the present application the numeral 1 designates thecondenser tail pipe of a pressure still ofthe type`described, y

and the numeral 2designates the closed receivingdrum into which'thistail-pipe disgauge'glass, vas shownatB. Into `the top of the drum' thereis connected a gas pipe `which .leads to a high pressure gas man1- fold5. A valved connection 6 at some rpoint along the high 'pressure gasline 5 opens into a low pressure gas main y7. In accordance .with myprior patent above referred to the Valve in this connection 6 will beused for releasing. all of thegases formed v in arelativelylarge'nu'mberfof stills connected to thehigh pressures linel, the

lpressure in this line and in al of thestills being thereby keptconstant and unlform throughoutthe system. Into the bottom of 4dica-tedat 12. Near the to each receiving drum 2 there` will be tapped a liquiddraw-off connectionl 8 which joins the Adlstillate line 9.

In accordance with the present invention.l

so y

I make a connection to the distillate line 9 as by the pipe 10 and leadthis connection to f the first of a series of closed treating tanks. Inthe drawlng I have for clearness and .simplicity of illustration shownlthepipe 10 vas extendlng to the bottom 'of a closed tank l1 designed torepresent an acid treating tahnkz The submerged end-Lof` the line 10fw1l1, in general, be equipped with-a distributing device, such as aperforated spiderinof the acidtreating tank 11 there will e an .overflowconnection 13, from which. a line 14 extends to the bottom of the secondclosed treating receptacle 15 which is represented asof the sameconstruction. The receptacle lfmay be a washer for washing out theentrained acid from the fluids under treatment. 'Be4 yond vthe washer 15there mayv be a soda,-

treating tank 16 and a'iinal washer 17, illustrated as of the sameconstruction. There w1ll usually be one or more settling tanks in thesystem, as 'is well understood, but I havev made no attempt toillustrate these. yFrom the last of the closed treating chambers, orreceptacles, 17, the overflow line 18 leads `into the bottom of aseparation tower 19, which'may bein the form of a vertical cylinderpreferably mounted alongside of and of thev same height as the treateddistillate storage tank 20. The separation tower may have a dam 21dividing the bottom of the tower midway between the point/of en` tranceofthe'line 18 and the' connection 22 from' the tower into thevbottom ofthefgstojrL age tank. The darn 21 may be of ah'eight abouty half that ofthe fsep'aration tank.

ated in the following manner:

'cordance with the p-resent invention opery A liquid distillate, such asgasoline, produced within the pressure stills will drain` continuouslythrough the condenser tailpipesl` into the receiving drums 2, where l1twill collect under the pressure'of the operation, for example, 5atmospheres, thispressurejbeing kept constant by controlling the escapeI the incondensable gas formed ini the operation from the high pressuregas line 5 into thelow ressure main 7 by the I vvali/'ed by-pass 6. lhen the still is in nor- Vmal Ioperation the'fdistillate,therefromcontinuously accumulating lin the receivingA drum 2 will be continuouslywithdrawn through the valved connection 8 at the base of the drum intothe distillate line 9, the

valve being regulated so as' to maintain a constant level in the drum.From-the distillateline 9 the crude gasoline distillate will.

How through the pipe 10 to the acid-treating tank 11 to be thereinsubjected to the refining action of the sulphu'ric acid. When the levelof the oil layer floating upon theacid in the tank 1l reaches theoverflow pipe 13 '20 oil will discharge through the latter into thewashing tank 15, thence tothe soda-,treating tank 16,' through thefinal'washer 17, and out b-y the line 1 8 to the separating tower-l9.@verflowing the dam in the latter the distily late will pass into thestorage tank20.

The flow of "distillate through the acid and alkali treatment apparatusabove described and into'the storage tank'is obtained without the use ofany pumpingapparatus whatever, but solely by the -iltiliza-I 'tion ofthe constantly-maintained pressure in the receiving drums. 2. Asdescribed, the contents of these drums is subjected to a uni-l formpressure of incondensable gas regulated by a valved by-pass 6. Forexample,

- the lreceiving drums 2 may be operating v 'under a constant pressureof incondensable gases of iveatmospheres. The .valves in the liquiddraw-off pipes 8 fromeach re- 40 ceivingdrum may be so set as Yto causeAa drop in pressure oi pounds through the valve, giving a pressure ofabout 2O pounds per square inch in the distillate line, 9 and at theentrance of the line 10 which leads v1.1.5 to the treating receptacles.kSince the distillate is condensed and collected in the relieved, aconsiderable percentage oi this gas G0 will be immediatelyliberated'and. the disi tillate line 9 willtherefore contain a mixed'luid, `partly gas Iand partly liquid. The gas and liquid will flowtogether into the line l0, and through the entire series of treatingtanks described.` Furthermore, there will necessarily be adrop'V inpressure along the length of the treating system, as the'result oit`which a further quantity of gas will come out vof solution in the oil.llt vvilltherefore be apparent that not only'will the treat- -ing systemreceive mixed iluids initially, but there will be a considera-bleevolution oic gas within the .system itself. rlhese re-v sults l hold tobe highly advantageous for. several reasons.A Thus, the .gas initiallyen tering the system with the liquiddistillate, as well as gases comingout ofsolution during the treatment, Vserve to effect ya very thoroughagitation o" the oil `and the treating liquids, which agitation makesformore intimate Contact and adds to the eiciency of the treatment, inso far as the liquid distillate itselie is concerned. T he effect of thegas in this respect may be compared to that of air, the use of which foragitation purposes in thefacid and alkali. treatment of oils is-wellknown. AFurthermore, the lmanner of operation described has theadvantage of treating, that is, refining, the gas simultaneously withthe liquid vand in the same apparatus As a result ofthev treating proc,`

ess, therefore, there is obtained not only a refined liquididistillate,capable of being marketed either with" or without further `jeining,butalso treated gas which' may be taken from the storage tank 20 and sepa-I rating tower 19 by the line 24l directly to .A

absorbers in which it may be dissolved in reiined heavy naphtha to lowerthe specificA gravity thereof vand produce a' marketable productdirectly.

Practically the entire quantity of gas dissolved in the oil will havebeen released therefrom by the time the oil 'reaches the 'sepa-rating'-tower 19. 'The use of the dam 2l somewhat assists the separation-j ofthev gas bubbles from the liquid inthis tower, there being necessarilycreated an'ascending current of liquid at the inlet side which willcarry the `entrained gas bubbles to the surface. ln general, however,there will be a slow liberation of gas from theJ oil for some time afterit goes to.storage, and .ll therelio.

fore prefer to close the top "of 'the storage tank 20 and 'carry ed theliberatedr gases Aby the connection 23 to ther top of the tower.

19,'rom .which they will-enter the line 24 and -be utilized asdescribed.

ln the foregoing description of the v operation of the apparatus I haveassumed that the receivii'igl drums z2-were released individually bytheir valved connections into the'distillate line 9. lt willbeunderstood,

of course, that it is possible `to open wide the valued connectionsbetween the individual receiving drums and-the 'distillate line,carrying the latter under the lpressure of the drums, and releasing thepressure from the line 9 intothe line 10 by a valve. at the entrance tothe latter. lll/'hieldl of the valve at-the entrance these methodsv ofcontrol will be employed will be dependent vupon the exact arrangementof the receiving drums andl o'ftheir draw-ofi' connections. Thus, forexample, if the receiving drums are at different horizontal elevations,orhif it is desired to meter the distillates produced 'in' theindividual stills independently, it would be required that eachreceiving drum be released independently distillate line. Ifv all'of thereceiving drums were at the same level, however. and all drumswere/connected by connections of the same resistanceto the line 9, thisline could be advantageously carried-under the drum pressure, therelease of. liquid pressure for the Awhole series -of stills beingobtained by x lof the line 10. In general, the pressure through thetreating system will drop continuously, so that when the treateddistillate and gas reaches the-*tower 19 there will only be suflicientpres- 'sure to raise the level ofdlstillateto the run,-

ning level of the tower'and its connected .tank oritanks-plus the veryslight pressure required to force the gas issulng from the pipe 24'through the absorber system to which the latter may be connected, orinto the mains or gasometer, if -there' be no absorber system employed.The pressure with-'- lin the treating system` may, however, be

raised at will to any point short ofthe pressure available in t-hereceiving druinys,e1ther the line 18 or if -th'estorage tank is capablefof withstanding pressure by throttling the line 24. It will lthat asthe` pressure within the'continuous treating system is increased, thepercentage of material handled*E in the gaseous lphase within the systemwould be decreased, the

`gas being maintained `insolutionl in 'the liquid by the pressure. As anadditional means for decreasing the volume of gas handled by the system,l may employ a gas tank 30 on the line 10, -any desired quantity of gasbeing releasedA through the valve 31 at the top of this trap. Myinventionthre fore, offers not only a means for continu ously andsimultaneously treating the dis` tillate and gas produced by thecracking stills, but also a means of regulating the relative proportionsof liquid vand gas handled in the treating apparatus.

`While I have in the foregoing described in considerable detail aprocess in accordance with my inventionand some variants thereof,together with a form of apparatus especially designed for the carryingout of the process, it will be understood that these details areillustrative only and that the invention is not limited to the preciseopera- -as such limitations form a through its own valve into the beunderstood' tions or apparatus described, except inso far part ofthe'accompanying claims, in which it isl my intention to claim allnovelty inherent inthe invention as broadly "asis permissible in view ofthe prior ar VVhatvI claim as new and desire to secure by Letters Patentis:

1. The method of refining petroleum oilswhich consists in maintaining abody of o il under a substantial pressure of hydrocarbon gas, in forcingthe oil by'- such pressure through a body of an oil-treating reagent,whereby the loil and the hydrocarbon gas dissolved therein aresimultaneously refined and partially releasing the gas pressure uponthein are simultaneously refined.

3. The method of refining petroleum oil which consists in continuouslycollecting a distillate of such oil under a substantial pressure ofdistillation gases, and fcontinuously forcing the collected oil by suchpressure through a treating apparatus in which `the oil is subjected tothe action of a refining reagent.

4. The method of refining petroleum oil which consists in continuouslycollecting a distillate of such oil under a substantial pressure ofdistillation gases, continuously forci ing 'the oil by such pressurethrough a closed chemical treating system and separating and collectingthe treated gas and liquid issuing v 'from the said closed system.

5. The improvement in the lmethod of con tinuously dissolved hydrocarbongases with an fim miscible liquid reagent which .consists yin performinthe treating operation in aclosed system under pressure ofsaid'hydrocarbonv gases and varying the pressure of said gases withinthe system to control the proportions of gas and liquid treated therein.

6. The method of refining petroleum oils which consist in lmaintaining abody of oil under a substantial'pressure of hydrocarbon treatingpetroleumoils containing gas, and forcing the oil by-such pressuresuccessively through'a series of liquid oiltreating reagents, said.reagents being immiscible with the oil, partially releasing the gaspressure uponthe oil in each of said successive treatments, andcollecting the treated gas andliquid oil issuing from the said closedsystem.'

EDGAR M. CLARK.

